1. Field of the Invention
The present invention relates to a method for fabricating a light-emitting diode (LED) device, and in particular it relates to a surface-roughing process in fabricating an LED device.
2. Description of the Related Art
Light-emitting diodes (LEDs) have two configurations. The LED that has electrodes arranged on the same side of an LED chip is called a horizontal LED. The LED that has electrodes arranged on the opposite sides of an LED chip is called a vertical LED. A current path flowing in and out of a semiconductor light-emitting layer of the horizontal LED needs to be turned in a direction horizontal to the LED chip. A current path can flow in and out of a semiconductor light-emitting layer of the vertical LED without turning in different directions.
The LED chip of the LED device usually grows on a substrate wafer by an epitaxial growth method. In fabrication processes of the LED device, however, the substrate wafer need to be cut to fabricate the individual LED chips for epitaxial layers to grow on the LED chips. The loss due to the substrate wafer sawing process is high when the LED chips have a small area. Therefore, the total light-emitting area of the substrate wafer is reduced. Further, a sapphire carrier removal process is required to be adopted in the conventional fabrication processes of the LED device. The sapphire carrier removal process is too complex to control the fabrication cost and yield.
Thus, a novel LED device and a method for fabricating the same are desired.